The Stovebolt Site Forums The Shop Area Engine Shop 235 crank install procedure

I'd like somebody to describe the procedure for installing a fresh 10/10 crank, shimming the caps and installing the rope seal in a full-pressure '54 235. (is that a long sentence or what? ) I have the '54 shop manual, but I want to know how you guys do it.

Thanks again,
Chip

Thought for the day: When a new motor pounds out a crank bearing, is it a mistake or act of God?

Just how the shop manual says Chip , It's a tried and proven process .
Keep it spotlessly clean --- take your time ..

When installing a new crankshaft in a block the first thing you do is make sure the block and crank are clean. Install the block half of the main bearings [do not install the rope seal now] in their respective journals, lift the crank and carefully lay it in the bearings, install the cap half of the bearings in the caps and carefully install them [ make sure the correct cap goes in the correct lacation], oil the threads with engine oil and install the bolts, torque them to the proper specs. Some people use plasti-guage to check the clearances, if you do, this should have been done prior to installing the caps. After the bolts have been torqued, if you used plasta-guage remove the caps and check the clearances. If you didn't use plasta-guage use your hands and turn the crank over, it should turn easy. If you have a dial indicator check the crank for end play,if every thing checked out good, now remove the crank and prepare to install the rope seal. Install the rope seal dry! Place the rope seal in the groove of the block with your hands and then use a hammer handle work it down in the groove, now use a razor blade or very sharp knife and cut the rope off flush with the block. I usually use the hammer handle as a back up and cut the seal from out side toward the handle. Do the same for the cap. Now lube the bearings and the seal surfaces of the rope seal. I put a small bead of no.2 permatex on the block leading from the seal to the outer edge of the block where the cap meets. This will prevent any oil seeping through. Oil the threads again and torque the bolts to the proper specs. Now turn the crank over, it will probably turn a little hard but that is to be expected.
Now when installing the rods use some kind of thread protector so the rods DO NOT HIT THE CRANK !! I have seen perfectly good overhauls ruined by rod bolts knicking the crank and in just about 20 minutes the bearing seeze up. When the rods and pistons are installed I would advise using plasta-guage to get the correct rod bearing clearance.
This is pretty long but I hope I have helped you along.

Plasti-gauge SUCKS!!!It is waste of time and money
Sorry Racecarldad but you know I'm right

I agree with everything else...but I spin the crank with every cap torqued...and use white grease as an assembly lube

If you can afford to measure things properly DON'T try to put a motor together

Pro and cons are looking good so far. Jim is "absolutely" correct on the "white assembly grease". I put an engine on white sheets and use white assembly grease so that if any contaminants show up I will see them and can start all over. Keep your engine covered when not working on it. Clean, Clean, Clean. Darn near hermetically sealed. Best thing is let your wife watch- she will spot any dirty stuff (I know from experence.LOL) Sounds like you will be on the road soon. Sounds great!!!

Chiphead, lots of reports out there that the new style non asbestos rope seals are not to good, but I have no experience those kind.I have used NOS asbestos rpoe seals with excellent results. Oly, you ought to try using an engine stand as it takes an a lot of starch in them sheets to hold up an engine.

I had heard the same thing about the newer rope seals on a Pontiac BB. Tony, you got any asbestos seals left? I hate hate hate oil leaks on a clutch. BTW, what oil clearance do you guys run on mains/rods??

Whats the procedure for setting the cam/crank gear alignment? My shop manual says to do it with the crank gear off, but my gear will be on when I bolt the crank in.

Chip

Can Oly dry-clean his engine stand? That'd make clean up easier.

[ 01-11-2002: Message edited by: chiphead ]

Chip, No I have none left. Stovebolt engine Co has the NOS rope seals for about 5 bucks a set. I buy them on Ebay when I see em.The main and crank bearings are supposed to be .0015-.003. .002 is a nice figure. If you are having the crank ground and really care about clearances, have the machinist measure the assembled bearings in the block and then he can grind the crank to fit.If he grinds the crank to the dimensions listed in his manuals, the bearing oil clearance is usually closer to .003.Its ok, but bleeds off some oil pressure.Intstall the cam before you drop in the crank for the final time and leave the gear off the crank.Its easier to feed in the cam without nicking the cam bearings without the crank in the way. How ever, you can do it with the crank in place if you are very careful.Anyway , just line up the dots marked on the gears and drive the crank gear home carefully with a piece of pipe that fits over the crank snout.If you are using a cam other than a stocker , you MUST degree in the cam.If you have doubts about degreeing, get a performance book that shows in detail how to do it.If the cam timing need to be moved, you can get crank gears that have multiple keyways from Clifford .Since the cam gear is pressed on you can't easily alter its position. You may be able to use an small block V8 offset key on the crank gear , although I am not for sure about that.

To find the crankshaft to brg clearance: Torque the main cap with the brg in place
Next put a snap gauge or self-centering bore gauge in the hole.LOCK....
Mic the snap gauge /mic the crank and subtract.......real clearance!
I use self centering bore gauges.These I 'Zero in the brg.I them mic the crank and
put the gauge in the mic on a stand ....the number is the clearance in tenths of a thou!
If you don't have really good stuff you just have to be more careful

If you undo one of the main or rod bolts and tap the cap the GAP between cap and rod or cap and block is the crush!

This gets repeated for each bore....rod or main.

If you use a bore gauge a mic stand and rod vice is a good investment

I use gauge blocks to check the mic and bore gauge.......

chip if you need any help with this call me i am off on monday and get off daily around 10.30 am i am going to sel the 235 out of my truck soon if you know any one looking putting in a 250 and turbo 400

I'm sorry J.H. Proffit but for us folks that don't have all the fancy guages, we use plasta-guage and in 35 years I never had a bad experience with it so it can't be all that bad. You must have had a very bad experience with it to be so outspoken on it. I have seen an overhaul saved by using it, the crank and bearings were marked for one size but the bearings were not the size they were marked and the mechanic using plasta-guage caught it.

OK Here's the point.......You have 35 years doing it wrong.......works for you.You are just lucky!
BUT don't tell somewone with NO experiance that it's OK cause.... it's not!
Plastigauge is JUNK..........so is Bonamme in the carb to make the rings seal and draggin the car/truck in gear to get the motor unstuck ect,ect,ect

There is nothing FANCY about having the right tools for the job.
Do you do everything with a hammer and vice-grips?
I bet you care enough to have a FANCY torque wrench
I bet you may have a FANCY Mic........What do you do when someone tries to close
your 0-1 mic.?

Yes I have some real expensive real fancy tools in a wooden tool box you have to step up to look in the top of.........But basic tools are nessary telling someone to start with less just isn't right.....sorry

Jeez, I guess I am doing it wrong too. I look at Plastigauge as a 'range' measuring tool. Plastigauge is NOT designed nor intended to give you an exact clearance reading. If the Plastigauge is squished out really flat, you know that the clearance on that bearing may not be adequate. Further investigation (inside mics, snap gauges, ect) will be required. The same is true if the Plastigauge is not squished very much.

Plastigauge is just intended to check the bearing manufacturer and crank grinder's work--it is just intended to catch a problem, not be the end/all of bearing clearance measurements.

Inside mics, snap gauges, ect are far more accurate and would be the 'right' way to measure bearing clearances. But there comes a point in ecomomics--how much does a set of inside mics cost? Could someone who is building his first (and maybe only) stovebolt justify the cost of these tools?

Maybe the correct way to handle this would be to have the machinist assemble the short block, but labor is not cheap. Following more of the same logic of not having absolute state of the art tools will preclude the hobbiest from doing any on his own engine work. If I were assembling a race motor or something rare, I would have ALL the neat trick tools to do the job right.

As long as the clearances are right, the motor will not know whether you used Plastigauge or precision measuring tools. It all comes down to individual choice. Yes, precision measuring instruments AND the accompanying skills to use them correctly are superior. If the machinist and bearing manufacturer did their jobs right, I can justify using a $2.00 piece of Plastigauge just to check things one final time rather than several hundred dollars for tools I would only use once. But, I have been doing things wrong all this time, too.

Plasti-gauge is a joke. Dont waste your money with it. Just put it together and see if it turns.Its a crap shoot. If your doing a inline and you have to shim the mains you surly are wasting your time with out the correct tools.I have proven this time and again by plasti-gauging the same main several times Never geting the correct(or same) measurement.
If i ever saw a machine shop us it i would pick my stuff up and leave.Plain and simple its for the hacker that does not understand engines or build engines that set around the rest of there life.I know the engines that i have built no 2 bearing inserts are the same.I have spent many hours on a motor swapping inserts from one rod/main to another to get the correct clearance.Also it has taken me 2-3 sets of bearing to get a motor were it belongs.Taking a peice of candle and putting it on the crank and crushing it down and measuring it with a peice of paper that was printed in some foreign country, come on get real.Its plain and simple hacker and lazy .You may have gottin away with it but it will bite you in the a## some day.You just lucked out on the few you have done. Just think how good you plastic -gauge is with the local CRAPA deleiver boy bringin it to you on the dash of the truck with the headefroster on. IT DONT WORK!!!!

My point is don't try to do this without tools,a good torque wrench,a mic...They aren't that expensive and atleast snap gauges.If you figure what the machine shop charges for assembly
you can buy all of this and maybe learn something.
Yes it takes skill and some time.You have to be able to use these items properly.
Try to do a frontend alienment with just a yardstick! There are people that can do it.Not me!
I learned a long time ago that I needed better tools than the machine shop had to check em
The Biggest Gerstner tool box you ever saw.......well THAT was me being FANCY!!!

Well, I guess I had better get ready to eat some crow--is it any better with lots of ketchup???

I was thumbing through my latest Harbor Freight catalog and found a 6pc. set of telescoping gauges for the sale price of $9.99. I thought they would be almost as expensive as an inside micrometer, but these are cheap. I then dug out an old Enco catalog and their price is the same for the Enco (import). The highest Mitutoyo is around $100.

Thanks for the lesson Jim and Bruce. Is crow better barbequed or oven roasted :p

Yeah, I even own a set. Fun to play with and they look impressive sitting next to the engine stand.One of these days I even may figure how to use them.

I,m sorry boys, But just owning the tools,
Don't mean you know how to use them,or read
them.
There is a feel to mics.
30 years in job shop trade.
Typing is harder.

Don King

Please buy a set of Starret snap gauges.....I got a cheap set to carry on the road they have the wrong radii on the end OK for big work not this crank stuff

Yes mics have a feel you have to get the touch.......but it's not Rocket Science!

Snap Gauge 101-

Hold the gauge in one hand and close it with the two fingers on the other.As you put it in the bore MAKE sure the handle is not 90 degrees to the bore tighten the gauge and draw it
overcenter to the bore as you withdraw it, NOW mic
It takes practice but only a little to start to make you good

Any Questions?
Anybody want to add some tricks?.....I know you guys got em

And RCDad I'm glad you see my point I really wasn't messin with you....you know that.

Jump it 2ton anytime.........Here's your chance to infect others with a wonderful trade!

Jesus H Chrysler, wow! I didn't mean for this thread to turn into a barroom blitz.

Some clarification: I am young, (26) but I love working on engines. I have rebuilt or helped rebuild everything from '20s era hit & miss engines, '40s era John Deere "B"s '60s era boat motors, and a '70s model dirt bike. After I build my chevy, I've got a '73 scout to restore, a Yamaha street bike with a rod knock, and two '67 Poncho 400 motors to do something with.

I do not have a problem with buying the correct tools and parts to do a good job. I have saved my money for a long time so I can do this right.

I have the following tools:
Set of outside mics, graduated at .001".
A set of inside snap gauges.
Degree wheel and dial indicator.
5 HP direct drive air compressor
Engine stand and hoist
Air tools
"clicker" style torque wrench.
bench grinder
full compliment of standard tools
Clapboard dirt-floor garage.

Am I missing any tools?

And one '54 Bel-Air that I want to drive to Panama City, Florida for Spring Break.

Everyone on this board has been so helpful, and I thank y'all for it!

PTE359, I'll try to call today from work. I usually don't get home till 6 pm.

The friendly ribbing adds a close-knit feel to the people who hang out here. But sheesh, lighten up on the eye-poking, guys!

Chip

Racecarl no crow man.You have showed me many things that i did not know. I went and bought my measuring stuff used cause no one would tell me were to buy it.So....i got screwed and relized the stuff was not that expensive.No personal digs just B.S. Again its hard to show how much of a stone crusher you are on the puter(thats me).If i did not care about someone learning i would just laugh and not post. I really dont like crow but chicken will do. :p

Get out the way Chip we ain't fightin just discussin a few things.
Fightin looks entirly different.
Because we all care about what we do we all have strong notions but this is not a discussion of personal hygene or something like that.No name callin.....no Muthers.The old farts here do
care about eachother.
And Crow isn't nessary......it's not like someone turned this into a 'Two-pager'

Darn it!!!!! And I thought I was doing good assembling engines with a hammer and a piece of string (for measuring purposes only!)

JH, thanks for the primer on the snap-gauges.

Let me get this right:

So I snap the inside dia on the assembled bearing shells, then mic the snap gauge. Then I mic the crank journal and subtract the two measurements? Add/remove shims to set the mains to .002", lube bearings, install crank w/o rear seal and see if she spins? Also check end-play now w/ dial indicator and feeler gauge. Then remove crank, install rear main seal, re-install crank, with thin smear of permatex on front and rear caps. See if she spins again with a little more resistance? Am I right?

If I put a torque wrench on the crank snout, at what torque should the crank begin to turn with rear seal installed?

Chip

Yup, but the front cap doesn't need any sealer.The rope seal will add a lot of drag,so long as you rolled the seal in carefully, cut the ends off clean, no loose strands of the seal material getting into the cap joint you'll be fine. don't forget to lube the seal before you drop in the crank.

OK Now WE are going to fight!!!!

SHIMS?????? Are you out of your mind? Don't use shims in a 'Thinwall bearing' motor

Shims are for poured babbit!!!!

The reason we use thin walled bearings is first ease I guess but more importantly the conduct heat away from the crank quicker! Shims slow this process....screw with the crush which results in high spots and an out-of-round bore....SHIMS!!!!

If you want to do this right.......Put the Brgs in the block,torque them,measure AND TELL the crank grinder the size you want the crank......I have a machine shop agrees with my mics
but I'm lucky to have a grinder that takes pride in his work and knows I'm gonna check him.
If you are worried you just tell him to take 0.XXX+-.0005. That way there is less chance for a TOTAL error

Most guys leave the shims in place on the 54 block but it may make sense to grind the crank to fit the bearings without the shims.Does the shims or lack of shims affect the bearing crush or what?Or do the shims extend over the edge of the shell? Remember a street 235 putting out 160 HP isn't very stressed out.

Shims.......NO SHIMS......DO IT RIGHT!!!Shims are for poured brgs that you hand fit.Yes you must fit some brgs not just 'Put em in'

Sometimes I think Mavis knows more about typewritters than you guys about motor-buildin

WE ARE TALKING ABOUT DOING IT RIGHT THE FIRST TIME!!!!!!!

I do use self-centering dial-indicating 'Federal'Gauges cause you can see everything in .0000's.Including shell distortion.Even short car motors NEED the best!
Nobody ever told you guys to measure first!??????

Maybe I should have the shop balance the bottom end and install the crank while they're at it? I could do the rest easily.

The crank is already turned to dead on .010/.010. Is is possible to custom-grind the crank to fit and not worry about bearing crush and line-boring?

Should I have the shop press the crank gear on, or should I do that after the crank is in? How else am I gonna check the cam thrust plate alignment with the gears installed on the crank/cam?

*ding* round four....

Chip

Definitely have it balanced!

THAT'S IT!!!!!!!!! I'M UNBALANCED!!!!

Jim- these young pups don't want to listen to "real" mechanics anymore. They just want to "slam and bam" in crates, like Phat, and say they are a mechanic. Ya just gotta know something is wrong when Tony and Phat start agreeing on anything. I think they are just trying to confuse the new kids on the block. All the tools that Phat needs in his tool box are a screw-driver and a pair of pliers and lots of rolls of duct-tape to cover up his mistakes.

Oily

I'd beg to differ with you on several counts....I'ver had a bunch of mail and a couple of phone calls regarding this thread

People do want to do things correctly......it saves them money and heartache not to mention the redo time and such

Perhaps it's the gray wet winter that has you down on the guys here.
I suggest that most here ARE trying to help others.
Some are better than others at expressing themselves.I have had to stop and think how I really do things step by step.......I've been doing this so long that I can't understand grinding the crank without measuring first.....I know it happens

I have to agree with Proffit and Oly. I worked in a machine shop for a few years a long time ago. Found out how to measure about anything and never forgot. Using measuring tools is like riding a bicycle or setting valves, you never forget. I've had serious wallet problems with plastiguage and with machinists. Gotten to the point that I take my mics and caliper and standards to the machine shop and let them know what I have against theirs. Also try to keep the temp within about 10* as things expand and contract. Did that one time when I had set up a short block and measured it at about 40* and took the crank in at about 75* did the set things up with the machinist's mics etc and the crank was out bout .0008. Just my $.02.
Dennis

Dabond has it right, especially on thermal expansion. Helped on a study on the B-52 when we were first rigging for cruise missile carriage. Looking at a rotary launcher in the bomb bay, and showed thermal expansion of 6 inches across the width of the bay, with a temperature range of something like -50F to 140F. Steel isn't as bad and I don't have the numbers handy, but if you are going to measure something, be sure the temperature has been stable for a couple of hours. It would be best to take a temp reading on the metal itself, but not many have a surface probe for this. My wife got me a voltmeter that does everything, and came with a temp probe. Gotta love that gal.

chiphead: The 235 you have is an early 54 model.

Block should be casting/GM part number- 3701481.

It will also have the "small cam bearings", same
diameter as earlier 48 and up 235's. In mid 54
Chevy changed tooling and went to larger cam
bearings, from mid 54 thru 63.

When the later 54 235's were produced they did
not contain the shim paks with the mains.

Your block should contain crankshaft casting/GM part number 3701486, and came factory with babbitt overlay mains, and rod bearings.

The main bearing inserts in your engine are full
grooved dowel type, with no locking lips.

The later blocks 54 and up, came factory with copper lead alloy overplated bearings, on rods and mains.

This was the latest, new technology from GM engineers at the time. This is the same bearing material they were going to use on there "New"
V-8"s in 55.

It seems funny now, but back then this was a real
big deal, going to a full insert assembly. They
would no longer need the shim paks, which is the
wrong way to remedy the "oil clearance" problem,
in used bearings anyway!

The removal of the shims gives only a vertical
adjustment on the bearing, nothing in the lateral
direction. This distorts the bearings and will
cause wiping and overload and failure. This does
not cure the oil pumping either as there is no
way to close the bearing surface laterally.

The thinnest shim in the shim pak is only .002
thick, so this only allows for a vertical
adjustment of .002 anyway. Additionally, you
could not adjust less than this vertically, unless
one was to only remove a .002 shim from one side.
This you would not want to do, because it would
distort the housing bore, and possibly cause a
failure of the main cap.

To replace precision insert bearings in a housing
with a shim pak, is quite simple.

First you use your telescoping gauges, and mike
the bore size. Add or remove shims as needed to
obtain a "round bore" of the correct size ID.
Make sure that there are the same number of like
thickness shim's on each side of the cap, so
it will not distort.

Here are the sizes you need to fit to. This is the
insert bearing correct OD and position.

1. Front main- 2.8760 - 2.8770

2. Front intermediate - 2.9070 - 2.9080

3. Rear intermediate - 2.9380 - 2.9390

4. Rear main - 2.9690 - 2.9700


Make sure to position the front intermediate cap
with the "F" side, forward. Position the rear
intermediate cap with the "R" towards the rear.

Install your bearing inserts in the correct
positions, and torque the caps. Now measure.

Now measure your crank journals. If bearings
are to small ID, you will have to have the mains
line honed/bored. If bearings are to big ID, get
another set of the correct size. You could also get undersize bearing inserts and have them
aligned-honed to correct ID. This may be your
best bet.

The oil clearance to shoot for is .0015 .
You may go up to .002 . But try to keep it as
tight as you can to .0015. This will give you
much better oil control. At .003 clearance, you
have 5 times the oil throw off, as you do at
.0015 .

As JHP and Phat said, take your time. And ALWAYS
double and triple check all machine work. Your
paying for it, and if something goes south, you'll
pay for it, again!

As for checking with a torque wrench, install a
flywheel bolt and put your torque wrench there.
Thats what I always do. Without rear seal, should
turn with no more than 7 to 9 ft/lbs. . With seal in place, and lubed as Tony said, should
turn over with no more than 10 to 12 ft/lbs. .

Make sure to check rods for twisted/bent condition, and check bores for distortion.
The machine shop will fix you up.

The only tools that I think you may need would be:
A quality straightedge. Like Starrett or maybe
Brown & Sharpe. Use this to check the main bores
and cam bores for warpage/distortion or bowed
crankcase. Check deck and head surfaces also.

Another tool you may want to get is a set of
radius gauges. Use them to check main and rod
fillet radius on shoulders, as with a regrind
on the crank you can sometimes have what is called
edge loading. The radius is too large and the
insert will try to ride up on the radius. It will
soon fail.

Double check EVERYTHING!!!

And Good Luck.

Think Chevy!!


:rolleyes:

chiphead: I forgot to tell you, throw that
plastigage, crap away. Your micrometer will never
lie to you. Plastigage will not tell if bearings
are out of round or tapered. Waste of time!!!
Stovebolt Science 101....Class is out!!

Good Luck, and repost if your having any kind
of troubles!


Think Chevy!!!

Chevyman, thanks for the info. I read the long post several times, then thought about my motor.

This is where it gets truly weird:

My block date code is A 19 4. Thats Jan 19, 1954, right? My motor has the 2.150" cam bearings and shims under the main caps. It has dowel-pin mains and solid lifters w/ the three speed.

A little backstory may be appropriate:

I bought the car in 1990. Cherry, complete and had never been apart or modified. Gave it an in-car ring job. Drove until 1997 when the #6 piston broke in half and beat itself apart.

Dad brought the car to a fly-by-night shop that made its living by butchering Ferd Tempos. They butchered my car so badly I decided to redo it myself.

Bought a crank kit from a auto parts store. They told me NOT to shim the mains. (I didn't know any better!) Plastigauged the mains to about .0019. Cranked the engine up, and it overheated. Let it cool, fired it up and drove it 300 miles before the #2 and #3 mains wiped down to the copper and locked up. Luckily it seized in my parent's driveway.

Pulled that crank kit out, got a new one under warranty and shimmed it in at .0035". Slapped the motor back together and drove it 10,000 miles. Installed a Holley 390, fentons and HEI. Drove another 2K before the crank end-play knocked the bearings to pieces.

Now here I am. I am so freaking paranoid about crank installation because this motor has had 2 strange bottom end failures since 1997.

Any chance that overheated crank ruined my block or warped the caps? What should I have the machine shop check for?

Is a 235 crank this tricky, or am I just making this too complicated?

Chip :confused:

[ 01-15-2002: Message edited by: chiphead ]

Chip, these cranks aren't that tricky. One question, how did you install the balancer? Drive it on with a hammer? If so, that's why the end play problems. If you haven't already done it, drill and tap the crank for a balancer bolt.

Like I said.......SHIMS! Under the cap...under the brg in a high-speed motor are a bad Idea
I had no idea that Chevy was dumb enough to used em that late.Figures 'Car Motor'truck!
You have modified the motor and nodoubt want to use the new found HP

Get a NON-SHIM motor!!!!!

Assemble it correctly.....measure-measure-measure!!!

And if you see an old guy in a 39 GMC don't try racing me....you will break it again!